This PA has constructed between 1986 and 1990 years. With 600W PEP output it was at that time one of the
most powerful 432MHz power amplifiers in OK and first of such construction with GI14b radar tube.

Soviet radar tube GI14b was produced since mid of 50-ties till mid of 70-ties and later replaced by GI39b tube,
which has almost the same performance. Compare well known GS31b, resp, GS35b tube these radar tubes have lower
plate dissipation, only about 500W and much average shorter life time. But for amateur radio use on the end of
80-ties we had nothing better.

In 2006, after 1,5 year of heavy use by OK1TEH the tube has changed by new one and PA performance was measured
again.

Note: for lower output to input transfer, and improved
neutralization a teflon strip ca 35mm width was inserted
between grid ring and tube

Construction: aluminium casting with 10mm wall. Grid ring
from brass, silvered. Plate stripline copper, 4mm thick, used as well as heatsink for tube. Cathode ring made
from bronze, stripline from brass plate. All dimensions below.

This tube can be pushed to higher output power, aprox. up
to 800W+ RF, but due to lower dissipation of these radar tubes for SSB/CW operation only. If you want to get
higher output, use higher plate voltage up to 3 kV and more powerful HV transformer. But in such operation shorter
lifetime of tube shall be expected.